import java.util.Scanner;

public class Test1 {


    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        while(input.hasNextLine()){
            String str = input.nextLine();
            String ret = func(str);
            System.out.println(ret);
        }
    }
    public static String func(String str){
        StringBuffer sb = new StringBuffer();
        int[] array = new int[127];
        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if (array[ch] == 0){
                sb.append(ch);
                array[ch] = 1;
            }
        }
        return sb.toString();
    }
}
